A selected time interval of previously stored events generated by a number of computer network devices are replayed and cross-correlated according to rules. Meta-events are generated when the events satisfy conditions associated with one or more of the rules. The rules used during replay may differ from prior rules used at a time when the events occurred within a computer network that included the computer network devices. In this way, new rules can be tested against true event data streams to determine whether or not the rules should be used in a live environment (i.e., the efficacy of the rules can be tested and/or debugged against actual event data).